/*
 * Copyright © 2001-2011 Stéphane Raimbault <stephane.raimbault@gmail.com>
 *
 * SPDX-License-Identifier: LGPL-2.1-or-later
 */

#ifndef MODBUS_TCP_PRIVATE_H
#define MODBUS_TCP_PRIVATE_H

#define _MODBUS_TCP_HEADER_LENGTH      7
#define _MODBUS_TCP_PRESET_REQ_LENGTH 12
#define _MODBUS_TCP_PRESET_RSP_LENGTH  8

#define _MODBUS_TCP_CHECKSUM_LENGTH    0

/* In both structures, the transaction ID must be placed on first position
 to have a quick access not dependent of the TCP backend */
typedef struct _modbus_tcp
{
	/* Extract from MODBUS Messaging on TCP/IP Implementation Guide V1.0b
	 (page 23/46):
	 The transaction identifier is used to associate the future response
	 with the request. This identifier is unique on each TCP connection. */
	uint16_t t_id;
	/* TCP port */
	int port;
	/* IP address */
	char ip[16];
} modbus_tcp_t;

#define _MODBUS_TCP_PI_NODE_LENGTH    1025
#define _MODBUS_TCP_PI_SERVICE_LENGTH   32

typedef struct _modbus_tcp_pi
{
	/* Transaction ID */
	uint16_t t_id;
	/* TCP port */
	int port;
	/* Node */
	char node[_MODBUS_TCP_PI_NODE_LENGTH];
	/* Service */
	char service[_MODBUS_TCP_PI_SERVICE_LENGTH];
} modbus_tcp_pi_t;

#endif /* MODBUS_TCP_PRIVATE_H */
